GIS multi-criteria decision analysis for assessment and mapping of neotectonic landscape deformation: a case study from Crete

This study of drainage systems in a tectonically active region is based on the Geographical Information Systems (GIS) integration of data from an analytic hierarchy process (AHP) and a weighted linear combination (WLC) procedure with multiple criteria data. A set of thematic maps were produced, based on existing geological maps and freely-available ASTER Global DEM elevation data, using various geological information (i.e. lineaments and lithologies), geomorphometric indices (i.e. slope gradient, drainage density, stream frequency, and the topographic wetness index) and morphotectonic indices (i.e. amplitude of relief and stream length gradient) that highlight areas of neotectonic landscape deformation. The weights of the factors were determined using AHP and WLC. A neotectonic landscape deformation index (NLDI) is computed as the sum of the various weighted factors to provide a map of NLDI distribution across the study region (western Crete). The main objective of this study was to analyse and map the intra-basin spatial variations in neotectonic landscape deformation: five classes, very low to very high, were determined. High to very high deformation zones are linked with known and newly detected active fault zones. The methodology could be developed into a low-cost technique for assessing seismic hazard, guiding disaster risk reduction activities. It can provide an alternative to the Interferometric Synthetic Aperture Radar (InSAR) approach for highlighting zones of neotectonic deformation, particularly in regions where dense vegetation or snow cover renders InSAR ineffective.